Self-cleaning centrifugal separator



March 11, 1969 J. A. N. ROUSSELET 3,432,092

SELF-CLEANING CENTRIFUGAL SEPARATOR Sheet Filed Aug. 19, 1966 M rch 1969 J. A. N. ROUSSELET 3,432,092

SELF-CLEANING CENTRIFUGAL SEPARATOR Filed Aug. 19. 1966 Sheet 2 of 2 United States Patent 3,432,092 SELF-CLEANING CENTRIFUGAL SEPARATOR Joseph Antoine Noel Rousselet, Montalivet-Annonay, Ardeche, France Filed Aug. 19, 1966, Ser. No. 573,540 Claims priority, application France, Sept. 7, 1965, 4 68 US. Cl. 233 z2 Int. Cl. B04b 11/08 3 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to a self-cleaning centrifugal separator.

It is established that the centrifugal separation of liquid, viscous and solid ingredients is effected much more readily in bowls having overflow discharges than by removal through tangential suction devices, since the latter create swirls and eddies in the liquids whereby the separation is disturbed.

On the other hand, when separating to a high degree, it is not possible to remove the deposit while the apparatus is operating and the raw liquid is fed, as this causes losses of said liquid. It is thus necessary to stop the feed in order to recover a comparatively dry deposit.

The present invention aims at obviating such drawbacks. To this end, it relates to a centrifugal separator comprising a conical bowl with a wide mouth which discharges the purified liquid by means of a system of radial pipes combined, 0n the one hand, with an arrangement of a tangential spoon automatically moving forwards and backwards at intervals, which allows removing automatically any thick or viscous sedimental deposit while the apparatus is operating and discharging continuously, and, On the other hand, with further adjustable radial pipes and an additional annular separator for discharging a heavier liquid when separating two liquids having different densities.

Various embodiments of such a centrifugal separator are possible. Thus, according to one embodiment, the conical bowl is divided into two or three compartments by means of one or two annular separators provided with ports which allow the heavy liquid ingredients and the deposit to pass into the last compartment which is smaller.

Flow pipes are radially secured to the wall of the separator on the side of the larger compartment and discharge the lighter liquid under the action of centrifugal force when the bowl is rotating.

In the case of a second heavier liquid having to be separated, other pipes, the level of which is adjustable, are secured to a further annular separator in the second intermediate compartment.

The small compartment of the bowl is located towards the base of the cone and houses a big spoon or scoop which operates and travels intermittently to remove the thick or viscous deposits stuck against the side wall of the bowl.

According to another embodiment, said small compartment houses one or more suction devices which remove, continuously or discontinuously, the liquid in excess or the second liquid heavier than that discharged through the pipes, in order either to empty said compartment before or during the operation of the big spoon, or to recover the heavier liquid.

The axis of the centrifugal separator can be either vertical or horizontal, this latter position ensuring however a better gravity dischage of the deposit when the thick liquid is being separated.

Owing to the annular separator and the conicity of the bowl, the thick deposit moves after settling on the wall of the bowl and passes through the ports of the annular separator or separators so as to collect in the small compartment from which it is steadily picked up by the spoon. Thus the settling of the deposit onto the wall of the bowl and the discharge of the liquid are not disturbed although the removal of the deposit is effected by the spoon.

The invention will now be explained in further detail by the following description, with reference to the appended diagrammatic drawing which illustrates, by way of non limiting example, an overflow centrifugal separator for separating one or two liquids which deposit a very thick sediment.

In said drawing:

FIGURE 1 is an elevational side view of the separator of the invention, and

FIGURE 2 is a sectional view taken along line 2-2 of FIGURE 1.

In the centrifugal separator illustrated, the conical bowl 2 is divided into three compartments 3, 4, 5 by means of two annular separators 6, 7.

Discharge pipes 8 are radially secured to the wall of the separator 6 on the side of the compartment 3, and allow the lighter liquid 9 to be discharged when the bowl is rotating. To this end, said pipes have lengths such that they pass through the layer of sediment 10, the layer of dense liquid 11, and into a layer 9 of lighter liquid.

Furthermore, the annular separator 6 is provided with ports 12 distributed over the periphery thereof at a height lower than the thickness of the sediment layer 10, said ports allowing the said sediment 10 to pass into the compartment 4 as a result of the force exerted by the liquid 9. Furthermore, if necessary, a small suction device 13, the head of which is housed inside the compartment 4, sucks the liquid to be drained.

The additional annular separator 7 is used when a heavy liquid must be separated. It includes ports 15 provided at a height lower than the thickness of the layer 11 of heavy liquid. Pipes 14 are secured to said separator inside the compartment 3 and pass through the layers 10 and 11.

When two liquids having different densities are to be separated, the height of the pipes 8 can be adjusted so as to correspond to the different levels of said liquids.

A big spoon 16 is housed inside the compartment 4 and for removing the sedimental deposit 10. The extent of its penetration into the layer of sediment, its operation and its retraction are controlled in steps either manually or automatically.

A feed tube 17 disposed axially of the apparatus opens into a spray cone 20 which distributes the liquid to be purified over the bottom 18 of the bowl 2. At the time when the sediment is removed by the spoon 16, the feeding of said liquid through said tube 17 can be stopped if required.

The bowl 2 with its bottom 18 and its spray cone 20 is secured to a shaft 19. Said bowl is surrounded by a casing 2.1 having a circular cross-sectional shape and a portion 22 of larger diameter. Centrifugal force throws the light liquid 9 and the heavy liquid 11 into said portion 22 on their discharge from the flow pipe 8 or 14, depending on whether one liquid or two liquids are being separated. Pipes 23 and 24 allow respective discharge of the light liquid and the heavy liquid which flow by gravity.

When two liquids are being separated, the casing 21 includes a wall 25, the heavy liquid flowing out through the pipe 24 while the light liquid flows out through the pipe 23.

The casing 21 is also provided with a projecting portion 26 which ensures the tightness thereof by means of a door 27 which includes sight holes. Said door is removable in order to give access to the inner bowl 2.

Owing to the above arrangements, the centrifugal separator of the invention ensures the continuous and steady separation of the liquids fed therein, without any risk of the sediment clogging it.

What I claim is:

1. An overflow centrifuge comprising a conical bowl having a large opening, means for the introduction into said bowl, via said opening, of raw liquid from which fractions of various densities are to be separated, said bowl being driven in rotation whereby the fractions are separated into layers of varying densities which decrease from the inner peripheral surface of the bowl radially inwards into the bowl, an annular separator in said bowl at the inner peripheral surface thereat, said separator extending radially inwards at the inner surface of the bowl to form first and second compartments thereat, said separator extending to a depth in said bowl to retain all the liquid in the first compartment, said separator having openings at the level of the heavier fractions to permit passage only thereof through the separator, a radial pipe secured to the bowl for rotation therewith, said pipe having a first open end in the first compartment at the level of the light fraction to be separated from the liquid, and an opposite open and external of the bowl for the discharge of said light fraction from the bowl, a stationary housing outside said bowl with an outlet for the separate conveyance of the light fraction and means arranged adjacent the bowl and extending radially into said second compartment into the heaviest fraction therein to remove such fraction during rotation of the bowl and during continuous feed of the raw liquid, the latter said means comprising a stationary spoon member extending into said heaviest fraction and means for adjusting the depth of penetration of the spoon member into said second compartment.

2. A centrifuge as claimed in claim 1 comprising a second separator in said first compartment adjacent the first separator to define a third compartment between the separators, said second separator having openings to permit passage therethrough of fractions heavier than that of the light fraction to be separated, a second radial pipe secured to the bowl for rotation therewith and having a first open end in said third compartment at a level of a second fraction to be separated which is heavier than that of said first fraction, said second pipe having a second open end external of said bowl for discharge of said second fraction, said housing having a second outlet isolated from the first said outlet for the separate discharge of said second fraction.

3. A centrifuge as claimed in claim 1 comprising suction means extending into said second compartment for removing the fraction therein.

References Cited UNITED STATES PATENTS 347,702 8/ 1886 Evans. 1,l76,412 3/1916 Weston 233-20 XR 1,754,774 4/1930 Sharples. 2,199,848 5/1940 Bryson 233--21 XR 3,333,765 8/1967 Maurer 23322 1,481,426 1/1924 McEntire 233-21 HENRY T. KLINKSIEK, Primary Examiner.

US. Cl. X.R. 233-47 

